This invention relates to a lock device in which a cantilever-type locking arm provided on one connector housing is engaged with the other connector housing, and a lock release member provided on the other connector housing is operated to release the engagement of the locking arm to thereby release the connection between the pair of connector housings.
In FIG. 6 (Japanese Utility Model Publication No. 57-545), a cantilever-type locking arm c is provided on each of opposite side walls h of a male connector a, and extends rearward from an upstanding proximal portion d disposed at a forward side in the direction of fitting of the male connector a. A retaining projection e is formed on the free end portion of the locking arm c.
A guide groove h for the locking arm c is formed in each of opposite side walls g of a female connector f, and a notch i is provided in the groove h, and extends in a forward/backward direction. The notch i forms a retaining portion j for the retaining projection e. A release arm l is provided outwardly of the notch i, and extends forwardly from an upstanding proximal portion k at a rearward side in the direction of fitting of the female connector f. A push projection m is formed on the distal end of the release arm l in facing relation to the notch i.
In the above construction, when the male connector a is fitted in the female connector f, the locking arm c is inserted into the guide groove h, and the retaining projection e is engaged with the side wall g, so that the locking arm c moves in an elastically inwardly deformed condition. When the retaining projection e passes past the side wall g to reach the notch i, the locking arm is restored, so that the retaining projection e is engaged in the retaining portion j (FIG. 7). Upon restoration of the locking arm c, an impingement portion n at its distal end impinges on the inner surface of the side wall g, and this impingement sound is well transmitted to the exterior through the notch i. A complete fitting between the male and female connectors a and f is aurally confirmed through this impingement sound.
For releasing the condition of fitting between the male and female connectors a and f, the free end of the release arm l is pushed down to urge the retaining projection e by the push projection m to push down the locking arm c, and the retaining projection e is disengaged from the notch i, and then the male and female connectors a and f are disengaged from each other.
In the above prior art, the complete fitting between the male and female connectors a and f is aurally confirmed, and therefore in some environments of the operation, it is difficult to obtain this confirmation.